A Novel Strategy to Early-Transition Metal pincer complexes of the PCP/POCOP motif

Early-transition metal pincer complexes have shown fascinating chemistry. From the 1970s Fryzuk (and others) demonstrated the tridentate PNP- class of ligands were able to stabilise the reduction of group four metals and facilitate their binding of dinitrogen. This work has recently been extended to pyrole-based PNP ligands by Nishibayashi and similar, sturdier, frameworks have been used by Mindiola to catalytically facilitate the activation of strong C-H bonds (e.g. Methane, Benzene).
The PCP/POCOP class of ligands are closely related to these PNP ligands, with the central N- donor replaced for a formal C-. However utilisation of these ligands with early-transition metals has not been achieved due to their synthetic route usually requiring the oxidative addition of a C-H bond across a M(N-2) metal centre. This project will focus on developing an alternative route to (PCP)M/(POCOP)M complexes and studying their derivatization and reactivity towards small molecules. Ultimately the stability and modular nature of this class of ligands will be exploited to tune the reactivity of the metal centre.
Finally the crystallisability of these complexes will be used in order to facilitate their reactivity in different physical forms. Single-crystal reactivity has been shown to increase the selectivity of processes, however it is currently limited to the late transition metals. As such these compounds will make ideal candidates to investigate analogous reactivity with the early-transition metals.